Noise suppressing element for continuous track of crawler type vehicle and method of operating same

ABSTRACT

A rotatable resilient contacting element attachable to track shoes of a crawler type vehicle.

BACKGROUND OF THE INVENTION

Conventional continuous tracks for use with track-type vehicles such ascrawler tractors comprise a series of track links interconnected by pinsfitted with an external bushing. In such a construction, the track linkshave an inner rail surface upon which the track rollers and idler wheelsroll. The pin and bushing connections of these conventional prior artstructures provide a drive means for coaction with a chain-drivingsprocket whereby the track is forcibly driven by rotational movement ofthe sprocket.

Although such a track construction has gained wide acceptance, it issubject to several shortcomings, such as noise created by the bushingsimpacting upon the drive sprocket and the rail surfaces impacting on theidler. Such conventional structures are also subjected to a high rate ofwear and power losses due to these impactions and due also to thescrubbing action of the bushings against the sprocket as the track isdriven.

A recent development in the art of endless tracks for track-typevehicles is the provision of a drive lug located on the track shoesintermediate the pin and bushing connections to assist the bushings indriving the track. Although these mid-pitch drive lugs have beensomewhat effective in substantially eliminating a number of thedisadvantages associated with conventional endless tracks, otherdisadvantages, such as high noise and wear levels, have not beendesirably overcome. Exemplary of prior art attempts to reduce noise,wear and other shortcomings of endless track assemblies include U.S.Pat. No. 3,887,244 which issued to G. M. Haslett et al. on June 3, 1975,from an application filed Nov. 30, 1973.

Although the apparatus of that patent functions satisfactorily forsuppressing noise, its wear life is somewhat less than a desirableperiod of time.

This invention therefore resides in apparatus and method for suppressingnoise of a continuous track of a crawler type vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 1A are diagrammatic views of a portion of the track of acrawler type vehicle having the apparatus of this invention;

FIG. 2 is a diagrammatic enlarged view of a portion of FIG. 1;

FIG. 3 is a diagrammatic frontal view of the apparatus of thisinvention; and

FIG. 4 is a diagrammatic end view of the apparatus of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1, 1A, and 2, a crawler type vehicle 10 has acontinuous track 12 formed of a plurality of interconnected track shoes14. The track 12 is driven by a sprocket wheel 16, as is known in theart.

THe noise suppressing assembly 18 of this invention is connectable to asurface of a track shoe 14 for suppressing noise responsive to contactof the track 12 by the driving sprocket 16. The noise suppressingassemblies 18 are positioned at locations on the track shoes 14 forcontacting track wheels 19 (FIG. 1A) and/or the sprocket 16 (FIG. 1) atlocations between the sprocket teeth 10.

Referring to FIGS. 3 and 4, the noise suppressing assembly 18 has aframe 22 having first and second upright elements 24, 26 and a base 28having at least one opening 30 extending therethrough for connecting theframe 22 to a track shoe 14 by a bolt 32 for example. Each of theupright elements 24, 26 have an opening 34 for receiving an axle 36 ofthe assembly 18.

A resilient contacting element 38 is mounted about the axle 36. Thecontacting element 38 is of general columnar transverse cross-sectionalconfiguration and has a central opening 40 extending longitudinallytherethrough for receiving the axle 36.

The contacting element 38 has a length sufficient for positioning theelement 38 between the frame uprights 24, 26 and spanning the thicknessof the sprocket teeth 20. The outside diameter of the contacting elementis of a size sufficient for contacting the sprocket 17 with an outersurface of the element 38 and contacting an adjacent structure, forexample a portion of the frame 22, with an opposed surface of theelement 38.

The axle 36 has a diameter substantially, sufficiently smaller than thediameter of the frame openings 34 and/or the axle 36 has a diametersubstantially, sufficiently smaller than the diameter of the centralopening 40 of the contacting element 38 for transverse and rotatablemovement of the contacting element 38 relative to the frame 22.

Means 42 is provided for maintaining the axle 36 within the frameopenings 34. This means 42 can be of various construction. In thepreferred embodiment shown, the axle 36 has an annular groove 44 formedon opposed ends of the axle 36 for receiving a retaining ring 46.Washers 48 are positioned about the axle 36 each at a location between arespective retainer ring 46 and the contacting element 38. Each of thewashers 48 have an outside diameter greater than the adjacent frameopening 34 and an inside diameter less than the outside diameter of therespective retaining ring 46.

The frame 22 can be a unitary element or be a composite frame formed ofa plurality of elements. The frame 22 is of general U configuration andhas a base 28 having openings extending therethrough for receiving bolts32 and connecting the frame 22 to a track shoe 14. The preferred frame22, as shown in FIG. 3, is formed of first and second separate frameelements 54, 56 each of a general L configuration. Each element 54, 56has a leg having an opening for receiving a bolt 32 for connecting theframe elements 54, 56 to the shoe 14. The frame elements 54, 56 can beconnected to the shoe 14 with the element legs extending outwardly andaway from one another or with said legs extending toward one anotherwith the ends of the legs being adjacent one another.

In the preferred construction shown in FIG. 3, the frame legs extendtoward one another and a holding element 58 overlies the leg ends 60, 62and is connected to said leg ends. Openings can be formed through theleg ends 60, 62 and the holding element 58 for receiving pins 64 throughrespective coaxial openings of the holding element 58 and legs 60, 62.

Referring to FIGS. 1 and 1A, the outside diameter of the contactingelement 38 is of a size sufficient for compression of the contactingelement in response to contacting the track wheels 19 and/or sprocket16. In order to reduce wear of the contacting element 38, said elementis rotatable as set forth above and as hereinafter more fully describedand is formed of a plurality of separate discs 66 (FIG. 3). The wearlife of the contacting element 38 is improved by the unique connectionof the element 38 to the shoe 14. By rotatably connecting the element 38and sizing the elements of the assembly as set forth above, thecontacting element 38 will rotate through a few degrees in response tothe impact subjected upon the element 38 by the wheel 19 and/or sprocket16.

In the operation of the apparatus of this invention, the contactingelement 38 outer diameter is of a size sufficient for positioning theaxis B of the contacting element generally spaced upwardly from an axisA of the frame opening 34 with a surface of the contacting element 38being supported by an underlying structure, as for example the frame 22and as shown in FIG. 4. In response to forces exerted in the contactingelement 38 by the sprocket 16, the noise suppressing contacting element38 is compressed and the surface in contact with the frame 22 becomesflattened and the axis B of the contacting element 38 moves toward pointA, as shown by broken lines. During compression of the element 38 and/orsubsequent release from contact with the sprocket 16 or wheel 19, thecontacting element 38 is caused to rotate a few degrees about its axis,thereby presenting a different surface for contact by the wheel orsprocket in response to subsequent movement. By this function ofrotation of the contacting element 38, the operational life of thecontacting element is markedly increased.

Other aspects, objects, and advantages of this invention can be obtainedfrom a study of the drawings, the disclosure and appended claims.

What is claimed is:
 1. A noise suppressing assembly connectable to atrack shoe of a continuous track of a crawler type vehicle, comprising:aframe having first and second spaced uprights and being connectable to atrack shoe, said uprights each having an opening therethrough, saidframe including:first and second elements each of a general"L"-configuration, each element having a leg extending from theassociated upright with said legs each having an opening therethroughfor connecting the first and second frame elements to a track shoe withends of the frame legs adjacent one another, a holding element overlyingthe leg ends and having openings therethrough substantially coaxial withthe openings of the leg ends; and a pin extending through each of thecoaxial openings for connecting the first and second frame elements; aresilient contacting element having a generally columnar cross-sectionalconfiguration, a central opening extending therethrough, and an outsidediameter sufficient for contacting one of a sprocket and a track wheelwith an outer surface of the element and adjacent structure on anopposed outer surface of the element in the installed position on atrack shoe; an axle extending through the frame openings and the centralopening for connecting the contacting element to and between the frameuprights, said axle having a diameter substantially, sufficientlysmaller than at least one of the diameter of the frame openings and thediameter of the central opening of the contacting element fortransversely and rotatably moving the contacting element relative to theframe in response to contact of the contacting element with one of thesprocket and wheel track; and connecting means for maintaining the axlewithin the frame openings.
 2. Apparatus, as set forth in claim 1,wherein the resilient contacting element is formed of a plurality ofseparate discs.
 3. Apparatus, as set forth in claim 1, wherein theconnecting means comprises an annular groove formed on opposed ends ofthe axle;a retaining ring positioned in each axle groove; and a washerpositioned about the axle between each retaining ring and the contactingelement, said washers each having an outside diameter greater than theadjacent frame opening and an inside diameter less than the outsidediameter of the respective retaining ring.